From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f70.google.com (mail-pa0-f70.google.com [209.85.220.70]) by kanga.kvack.org (Postfix) with ESMTP id ED35982F69 for ; Thu, 21 Apr 2016 04:49:51 -0400 (EDT) Received: by mail-pa0-f70.google.com with SMTP id xm6so56452158pab.3 for ; Thu, 21 Apr 2016 01:49:51 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id m63si2406265pfm.104.2016.04.21.01.49.50 for ; Thu, 21 Apr 2016 01:49:51 -0700 (PDT) Date: Thu, 21 Apr 2016 09:49:46 +0100 From: Catalin Marinas Subject: Re: [BUG] set_pte_at: racy dirty state clearing warning Message-ID: <20160421084946.GA23774@e104818-lin.cambridge.arm.com> References: <57180A53.3000207@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <57180A53.3000207@linaro.org> Sender: owner-linux-mm@kvack.org List-ID: To: "Shi, Yang" Cc: Will Deacon , linux-mm@kvack.org, LKML , "linux-arm-kernel@lists.infradead.org" On Wed, Apr 20, 2016 at 04:01:39PM -0700, Shi, Yang wrote: > When I enable memory comact via > > # echo 1 > /proc/sys/vm/compact_memory > > I got the below WARNING: > > set_pte_at: racy dirty state clearing: 0x0068000099371bd3 -> > 0x0068000099371fd3 > ------------[ cut here ]------------ > WARNING: CPU: 5 PID: 294 at ./arch/arm64/include/asm/pgtable.h:227 > ptep_set_access_flags+0x138/0x1b8 > Modules linked in: Do you have this patch applied: http://article.gmane.org/gmane.linux.ports.arm.kernel/492239 It's also queued into -next as commit 66dbd6e61a52. > My kernel has ARM64_HW_AFDBM enabled, but LS2085 is not ARMv8.1. > > The code shows it just check if ARM64_HW_AFDBM is enabled or not, but > doesn't check if the CPU really has such capability. > > So, it might be better to have the capability checked runtime? The warnings are there to spot any incorrect uses of the pte accessors even before you run on AF/DBM-capable hardware. -- Catalin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org